Cycloidal ship propeller



Aug. 1966 K. BUCKLE ETAL 3268,010

GYCLOIDAL SI'IIP PROPELLER Filed April v, 1965 INVENTOR Karl .Blickle Eu qen Hflich Wilhelm Hub United States Patent O 3,268,010 CYCLOIDAL SHIP PROPELLER Karl Blickle, Bolheim, Engen Hflich, Heidenheun (Brenz), and Wilhelm Hub, Saarbrucken, Germany, assignors to J. M. Voith G.m.b.H. Heidenheim (Brenz), Germany Filed Apr. 7, 1965, Ser. N0. 446,202

7 Claims. (Cl. 170-151) The present application is a continuation-in-part of our copending application, Serial N0. 239,866, filed November 14, 1962 and entitled Cycloidal Ship Propeller.

This invention relates 150 cycloidal propellers, particularly for ships, said propellers having a blade Wheel body which is adapted for being rotatably supported and wh-ich blade wheel body carries a plurality of blades extending substanti-ally parallel to the axis of rotation of the body and pivotally mounted on the body. These blades are uniformly circumferentially distributed on the body along a blade circle Which is co-axia-l with the axis of rotation of the body.

With propellers of the cycloidal type, the blades are tilted about a central axis -thereof con=forrning to the axis of rotatable support of the blades to change the angle of attack of the blades, thereby to obtain propulsion in a direction at right angles to the axis of rotat-ion of the blade wheel body. The individual blades of the propeller are connected through a blade actuating linkage system, a so-called kinematic, which includes a central oont-rol disc cornmon t-o all of the blades and which is operable frorn outside the blade body for adjustin-g the linkage.

The linkage system includes at least one lever fixed to the respective blade, Which may =be termed a blade lever, and also includes a connecting rod linked to the blade lever and, furtherrnore, includes a crank lever pivotally connected in the region of the junction of the arrns thereof to the blade wheel body with one end of one arm of the crank lever being connected to the connecting rod while the end of the other arm of the lever is connected to the control disc.

With many ships employing cycloidal propellers, two =propellers are required to obtain the propulsive effo-rt desired and, When the ship is on a straight eourse, it is desirable to compensate for the respective torques of the two propellers by causing them to rotate in respectively opposite directions.

With known cycloidal ropeller blade actuating linkage systems as set forth, for exarnple, in United States Patent N0. 2,978,036, the drawback is encountered that, with propellers rotating in respectively opposite directions, the blade wheel body and the blade actuating linkage system has to be designed differently for propellers rotating in cloclcwise direction than for propellers rotating in counter-clockwise direction. This in turn means that for producing oloclawise rotating =propellers, machine shop drawings, models, devices and -similar manufacturing aids have to be produced other than what is necessary for counter-clockwi-se rotating propellers so that the cost for the manufacture and the stockkeeping of the propellers is considerably increased.

It is,- therefore, an object of the present invention to provide a cycloidal ship propeller, which will overcome the above mentioned drawbacks.

It is another object of this invention to provide a cycloidal ship propeller and in particular the blade actuating linkage system in such a way that the Same Type of blade wheel body may be employed for propellers rotating in cloelowise direction and for propellers rotating in countercloc-kwise direotion.

These and other objects and advantages of the invention Will appear more clearly -frorn the fol-lwlng specification in connection with the accompanying drawvings, in which:

FIGURES l, 2 and 3 diagramrnatically illustrate three embodiments of a r:ycloidal ship propeller With a blade actuating linkage sys tem ac cording to the present invention; and

FIGURE 4 is a view showing the propeller of FIGURE 1 with the contr-ol disc shifted 011 center.

General arrangement.ln order to overcome the drawbacks -outlined above With heretofore known linkage systems for cyclo=idal ship propellers, according to the present invention, the axis of the pivot by means of which the two-arm lever of the blade actua-ting linkage system is linked to the blade wheel body is arranged in a radial plane defined by the axis of rotation of the blade wheel body and the pivot axis of the respective blade actuated by said blade actuat-ing linkage system.

A blade actuating linkage systern designed in this way makes -it posslble -to produoe one and the saure type blade wheel body for propellers rotating in clockwise direction as wve1l as for propellers rotating in counter-clockwise direction. Thus, instead 0f providing two blade wheel bodies as was heretofore necessary, when employing a blade wheel linkage system according t0 the invention, only one type of blade wheel body is nece-ssary so that the costs for keeping stock and replacernent parts will be greatly -reduced and the replacement of the Parts will be greatly simplified.

Structural arrangement.Refer-ring now to the dralwings in detail, it should be noted that, in FIGURES 1, 2 or 3, the blades are illustrated in their middle position, i.e., in a posit-i0n in which the blade is tangential to the eircle on which the pivot axis of said blade is located.

As will be seen from the figures in the drawings in which the same elements have been designated with the same reference numerals, the blade wheel body 1 of the cycloidal ropeller, w-hich blade wheel body is rotatably journalled in the ship body, there is provided a control disc 3 common to all of the blades 2 and operable from the outside of the blade wheel body. In addition thereto, within said rotatable blade wheel body 1 there is provided a number of blade actuating linkage systems corresponding to the nurnber of the blades With Which the blade wheel body is equipped. For purposes of clarity, however, each of the various FIGURES 1 to 3 illustrates one blade wheel actuating linkage system only.

According to the present invention, the blade actuating linkage system as shown in FIGURE 1 is so designed that the lever arms of the tWo-arm lever linked by a flat link to the blade wheel body confine on the side of the link pivot an angle of According to a further developrnent of the invention, as shown in FIG- URE 2, the ratio of the length of the lever arm connected to the control disc to the length 01" the lever arm connected to the connecting rod is about 1.221. Also With a blade actuating linkage systern with a two-arm lever confining an angle of therebetween, as shown in FIGURE 3,

the Same ratio of the lever arms of the two-arm lever is advantageous.

Referring more specifically to FIGURES 1, 2 and 3 it Will be noted that the two-arm lever 7a is pivotally connected to the blade wheel body 1 by means of a flat link 7b. Furthermore, the double lever 7a Connected through link 7b With pivot 6 is so designed that its -lever arrns which are of equal length confine With each other an angle of 170. In the embodiment of FIGURE l, the piovt 4' connecting the two-arm lever 7a to the control disc 3 is spaced from the center 11 of the disc 3. In the ernbodiment shown in FIGURE 2, the ratio of the lever arm length of lever arm b of the two-arm lever 7a to the length of the lever arm a connected to connecting rod 5 is about 1.221, and the lever arrns of the two-arm 1ever confine With each other an angle of 170. Also in this case the pivot 4" connecting the two-arm lever to the control disc 3 is spaced from the center of the disc.

According to the embodiment of FIGURE 3, the lever arm ratio also is =approximately 1.221 and the angle confined by said lever arms a and b is 180. In this ernbodiment, the pivot 4" in contrast to FIGURES 1 and 2 connecting the lever arm b to the control disc 3 is located in the center point of the control disc 3.

By appropriately selecting the angles and/or the lever arms lengths f the two-arm lever it becornes possible to adjust the blade pitch to more favorable values than was possible with heretofore known designs of blade actuating linkage systems, so that, With the present invention, better degrees of efiiciency of the propeller can be obtained than were heretofore possible. Furthermore, by an appropriate design of the blade actuating linkage system according to the present invention, there Will be obtained the advantage that with thecontrol center in a osition out cf its central position the torques actin=g on the control disc and varying several times from positive to negative peaks during a rotation of the propeller will have approximately the same magnitude. Consequently, the peaks of the reciprocating forces in the individual joints of the kinematics will be reduced While simultaneously a more favorable lubrication Will be obtained than was heretofore obtainable.

In FIGURE 4 a cycloidal propeller according to FIG- URE 1 is shown With the control disc 3 shifted off center so that the osition of the four propeller blades A, B, C and D in the four quadrants Will be seen.

The center point 11 of the control disc 3 is displacecl on the transverse diameter from the center point of the blade wheel body 1 by a distance e towards the left. This displacement corresponds to a direction of attack of the force of the water on the propeller and thereby a direction of advancement of the ropeller and ol: the ship in upward direction (With regard to the drawing), as shown in FIGURE 4 by arrow p. In both positions A, C of the propeller blader 2 in Which the pivot axis 12 of the blade coincides with the point of intersection of the transverse diameter 10 With the blade wheel orbit 9, the blade is tangential to the blade wheel orbit as was the case before. In the two other postiions, B, D which correspond to an advancing movernent of the blade on the blade wheel orbit by 90 er 270 respectively with l'espect to the blade position A the blades are tilted out oft the tangential position, in such a way that the head of the blade at the top of the view is tilted outwardly, and at the bottom 0f the view the head of the blade is tilted toward the inside. That blade which is designated A is after a rotation of the wheel body in the direction of the arrow q of 90 in the position of the blade B, after a further rotation of 90 (180 counting frorn the starting position) it has reached the position of the blade C, namely, again a tangential position, and fin-ally, elfter a further rotation of 90 (270 from the starting position) it has reaehed the position of the blade D.

The Problem of designing a blade wheel body and blade actuating linkage system for cycloidal propellers Which can be employed for both clockwise rotating propellers and counter-clockwise propellers is by no means as simple as by merely pivoting the linkage to the blade wheel body on a line passing through the Center of rotation of the blade wheel body and the pivot axis of the respective blade. Many attempts have been made to find such a linkage but heretofore such linkage systerns have been defective in providing that the propeller will operate efliciently and substantially free of cavitation.

Freedom of the propeller from cavitation is extrernely irnportant, inasmuch as the reliability and safety of the ropeller depends largely upon this feature. The propeller at the sarne time must have a high degree of eificiency throughout the useful range of pitch thereof.

The structure disclosed in the present invention solves this problem satisfactorily for the first time and provides a suitable propeller construction which provides for efficient cavitation-free operation of propeller while one and the same blade wheel body can be employed fr both clockwise rotating and counter-clockwise rotating propellers. The blades can, of course, be reversed on the propeller body when the direction cf rotation of the propeller body is reversed and by forming the linkage connecting the control plate with the blade levers of flat members, such as frorn stamped sheet metal arts or flat cast, or forged members, the linkage members themselves can also be employed for propellers of both senses of rotation. It Will be evident that the provision of suitable blade actuating linkage system and a suitable blade wheel body in accordance With the principles of the present invention greatly reduces the cost of manufacture of the propellers and reduces the invent0ry of parts and the like.

lt is, of course, to be understood that the present invention is, by no rneans, limited to the particular comstructions shown in the drawings but also comprises any modifications within the scope of the appended claims.

What is claimed is:

l. A cycloidal ship propeller comprising: a -blade wheel body rotatable on a central axis, a plurality -of blades arranged along a circle concentric with said blade wheel central axis and in substantially uniformly spaced relationship t0 eacl1 other, pivot means pivotally supporting said blades on said blade wheel body and each pivot means defining a pivot axis for its respective blade, said pivot axes being substantially parallel to each other and to said central axis, each of said blades being capable of an oscillating rnovement about its pivot axis and about a middle position of the blade in Which the respective blade is tangential to the circle along which the pivot axes of said blades are arranged, adjustable control means common to all of said blades and movable selectively from a central position coaxial with said central axis of said blade wheel body into any one of a plurality of positions eccentric with regard to said central axis of said blade wheel body and vice versa to govern the oscillating movernent of said blades, a plnrality of blade actuating linkage systems respectively operatively connecting said adjustable control means with said blade pivot xneans so that each of said blades will be operable in response to a rotation of said wheel body and while said adjustable control means occupies any of its possible positions to carry out an oscillating rnovernent having the predetermined magnitude of the blade angles which correspond to the res1wective circular positions of the pivot axes of the blades during their circular movernen-t With said blade wheel body, each of said blade actuating linkage systems cornprising at least one lever operatively connected to the respective blade pivot means and also cornprising a connecting rod linked to said lever, each of said blade actuating linkage systems furthermore comprising a two arm lever having one of its arms connected to said conneeting rod and having its other arm pivotally connected at the center of said adjustable control means, a link pivotally connecting the two-arm lever in the region of the junction of the tvvo arms there-of to a point on the blade wheel body, the two arms of said twoarrn lever forming With each other an angle of approximately said point on the blade wheel body being located in a radial plane passing through the axis of rotation of said blade wheel body and through the axis of the pivotal connection of the respective blade With said blade wheel body and also being located betvveen said axes, the arrangement being such that f01' each blade and the blade adjusting linkage system pertaining thereto, in the central position of said control means, with regard to the direction of Iotation of said wheel body, said lever and said rod pertaining to said blade actuating linkage systern, are located behind said radial plane, said angle being located on the same side of said tw-o-arm lever as said 1ink.

2. A cycloidal ship propeller comprising: a blade wheel body rotatable on a central axis, a plurality of blades arranged along a circle concentric with said blade wheel central axis and in substantially unifor-rnly spaced relationship to each other, pivot means pivotally supporting said blades on said blade wheel body and each pivot means defining a pivot axis for its respective blade, said pivot axes being substantially parallel t0 each other and to said central axis, each of said blades being capable of an oscillating movement about its pivot axis and about a middle position 0f the blade in which the respective blade is tangential to the circle along which the pivot axes 0f said blades are arranged, adjustable control means common to all of said blades and movable selectively from a central position coaxial With said central axis of said blade wheel body into any one of a plurality of positions eccentric With regard to said central axis -of said blade wheel body and vice versa to govern the oscillating movement 0f said blades, a plurality of blade actuating linkage systems respectively operatively connecting said adjustable control means with said blade pivot means so that each -of said blades will be operable in response to a rotation of said wheel body and while said adjustable oontrol means occupies any of its possible positions to carry out an oscillating movement having the predetermined magnitude of the blade angles which correspond to the respec- Live circular positions of the pivot axes of the blades during their circular movement with said blade wheel body, each of said blade actuating linkage systems comprising at least one lever operatively connected to the respective blade pivot means and also comprising a connecting rod linked to said lever, each of said blade actuating linkage systems furthermore comprising a two-arm lever having one 0f its arms connected to said connecting rod and having its other arm pivotally connected at the center cf said adjustable control means, the ratio of the length of that arm of said two-arm lever which is connected to said adjustable control means to the length of the other arm of said two-arm lever being about 1.221, a link pivotally connecting the two-arm lever in the region of the junction of the two arms thereof to a point on the blade wheel body, said point on the blade wheel body being located in a radial plane passing through the axis cf rotation of said blade wheel body and through the axis of the pivotal connection of the respective blade with said blade wheel body and also being located between said axes, the arrangement being such that for each blade and the blade adjusting linkage system pertaining thereto, in the central position of said control means, with regard to the direc- -tion of rotation of said wheel body, said lever and said rod and also said two-arm lever and said link all pertaining to said blade actuating linkage system, are located behind said radial plane.

3. A cycloidal ship propeller comprising: a blade wheel body, a plurality of blades pivotally supported by said blade wheel body and having their pivot axes arranged along a circle in substantially uniforrnly spaced .relationshi-p to each other, said pivot axes being substanti-ally parallel to each other, each of said blades being capable of an oscillating movement about its pivot, adjusta'ble control means common to all of said blades and movable selectively from a central poistion coaxial with said blade wheel body into any one of a plurality 0& positions eccentric with regard to said blade wheel body and vice versa to govern the osci'llating movernent of said blades, each of said blades comprising a pivot and being oscillatable about a middle position thereof in which the respe-ctive blade is tangential to the circle al=ong which the pivot axes of said blade are anranged, a plurality of blade actuating linka-ge systems respectively operatively connecting said adjustable control means with said blades, each of said blade actuating linkage systems comprising at least one lever operatively connected to the respective blade pivot and also comprising a connecting rod linked to said lever, each of said blade actuating linkage systems furthermore comprising a two-arm lever pivotally cormected to said blade wheel body and having one of its arms :connected to said connecting rod and having its oflher arm pivotally connected at the center of said adjustable control means, the arrangement being such that for each blade and the linkage systern pertaining thereto the axis of the pivotal connection 0& the two-arm lever of the respective linkage systern with said blade wheel body is located in the radial plane whi'ch passes thr0ug h the axis of rotation of said blade wheel body and through the axis 0f the pivotal connecti-on 0f the respective blade with said blade wheel body.

4. A cycloidal ship propeller according t0 claim 3 in which, wiuh respect to the direction of rotation of said wheel body, each said blade acbuating linkag1e sysbem is located behind said radial plane pertaining thereto.

5. A cycloidal -ship propeller tcomprising; a blade wheel body, a plurality 0f blades pivotally supported by said blade wheel body and having their pivot axes arranged along a circle in substa-ntially uniformly spaced relationship t-o each other, said pivot axes being substantially parallel to each other, each of said blades being capable of an oscillating movernent about its pivot, adjustable contr-ol means comrnon to all 0r' said blades and movable selectively from a central position co-axial With said blade wheel body into any one of a plurality of p-ositions eccentric with =regard to said blade wheel body and vice versa, each o f said blades comprising a pivot, a plurality of blade actuating linkage systems respectively operatively counecting said adjustable control means with said blades, each 0f said blades actuati=ng linkage systems com-prising at least one lever operatively oonnected to the respective blade pivot and also comprising a =connecting rod linked to said lever, each of said blades act-uatirrg linkage systems (furthermore comprising a two-arm lever having one of its arms oonnected t-o said wconn-ecting rod and having its other arm pivotally connected at the center of said adjustable control means, link means linked on one band to said two-arm lever between the end portions thereof and being 0n the other band pivotally conne-cted to said blade wheel body, the arrangement being such that for each blade and the linkage system pertaining thereto the axis of the pivotal connection 0f said link means with said blade wheel body is located in a radial plane passing through the axis of rotation of said blade wheel body and through the axis of the pivotal connection of the respective blade with said blade wheel body, the ratio of the length of that arm 0f said two-arm -lever whi ch is pivotally connected to said adjustable control means to the length of that arm of said -two-arm lever which is c0nnected t0 said connecting rod being Witl1in the range of fr0m 1.2 to 1.

6. A cycloidal ship propeller acc-ording to claim 5, in Which each of said blades oscillates about a middle position in which the blade is tangential to the circle along Whi-ch the pivot axes of said blades are arranged, and in whi'ch the two arms of said two-arm lever confine with each other an angle of about degrees.

7. A cycloidal ship propeller comprising: a blade wheel body rotatable on a cenfiral axis, a plurality 01: blades pivotally supported by said blade wheel body and having their pivot axes arranged along a circle ooncentric with said blade wheel central axis and in substantially uniforrnly spaced relatio nship to each other, said pivot axes being substantially parallel t0 each other and also parallel to said central axis, each 0f said blades being capable 0f an oscillating movenient about its pivot axis, adjustable control means comrnon to all of said blades and movable selectively frorn a central position coaxial With said oentral axis 0f said blade wheel body into any one 0d? a plurality of positions eccentric with regard '00 said central axis of said blade wheel body and vice versa t-o govern the os.cillatirrg movement of said blades, each of said blades cornprising a pivot and being oscillatable about a middle position of the blade in which the respective blade is tangential to the circle along whi ch the pivot axes f said blades are arranged, a plurality 0f blade euctuating linkage systems respectively operatively con-necting said adjustable control means w1'th said blades so that each of said blades will be operable in response -t0 a rotatiorn cf said Wheel body and while said adjustable control means 0ccupies any of its possible positions t0 carry out an osoil- -lating movement having the predetermined magnitude of Uhe blade angles which correspond to the respective circular positions cf the pivot axes of the blades during their oimcular moveunent with said blade wheel body, each of said blade actuati-ng linkage systerns comprising at least one lev=er operatively connected to the respective blade pivot and also compri-sing a connecting rod linked to said lever, each 0f said blade acbuating linkage systems furthermore comprising a tvwo-arm lever havin=g o-ne cf its arms con-nected to said oonnecting rod and having its 0ther arm pivotally connected at the *center of said adjustable contro1 means, means including a link between the lever and wheel body pivotally connecting the twoarm lever in the region 0f the junction of the two arms thereof to a point on the blade wheel body, said point 011 the wheel body being located in a radial plane passing through the axis of rotation 0f said wheel body ancl through the axis of the piv0bal connection of the respec- References Cited by the Examiner UNITED STATES PATENTS 2413,460 12/ 1946 Main -149 X FOREIGN PATENTS 114,323 9/1929 Austria. 709,253 8/1941 Germany. 1029255 4/ 8 Germany.

285,911 10/1928 Great Britain. 721,374 1/1955 Great Britain.

EDGAR W. GEOGHEGAN, Primary Examiner.

SAMUEL LEVINE, Examiner.

E. A. POWELL, JR., Assistant Examiner. 

3. A CYCLOIDAL SHIP PROPELLER COMPRISING: A BLADE WHEEL BODY, A PLURALITY OF BLADES PIVOTALLY SUPPORTED BY SAID BLDE WHEEL BODY AND HAVING THEIR PIVOT AXES ARRANGED ALONG A CIRCLE IN SUBSTANTIALLY UNIFORMLY SPACED RELATIONSHIP TO EACH OTHER, SAID PIVOT AXES BEING SUBSTANTIALLY PARALLEL TO EACH OTHER, EACH OF SAID BLADES BEING CAPABLE OF AN OSCILLATING MOVEMENT ABOUT ITS PIVOT, ADJUSTABLE CONTROL MEANS COMMON TO ALL OF SAID BLADES AND MOVABLE SELECTIVELY FROM A CENTRAL POSITION COAXIAL WITH SAID BLADE WHEEL BODY INTO ANY ONE OF A PLURALITY OF POSITIONS ECCENTRIC WITH REGARD TO SAID BLADE WHEEL BODY AND VICE VERSA TO GOVERN THE OSCILLATING MOVEMENT OF SAID BLADES, EACH OF SAID BLADES COMPRISING A PIVOT AND BEING OSCILLATABLE ABOUT A MIDDLE POSITION THEREOF IN WHICH THE RESPECTIVE BLADE IS TANGENTIAL TO THE CIRCLE ALONG WHICH THE PIVOT AXES OF SAID BLADE ARE ARRANGED, A PLURALITY OF BLADE ACTUATING LINKAGE SYSTEMS RESPECTIVELY OPERATIVELY CONNECTING SAID ADJUSTABLE CONTROL MEANS WITH SAID BLADES, 